# Structures Vision Data Access Functions

This topic lists the Vision Data Access functions that get values from data structures as input.

Note: The Structure argument of the following functions must be a reference to the data structure returned by an Annulus, Circle, Cross, Fixture, Fixtures, Line, Mask, Point or Region function. The valid structures for each function are indicated in the description.

Function | Description
--- | ---
GetAngle(Structure, [Index]) | Returns the Angle value from the indexed Cross, Fixture or Region data structure.
GetCurve(Structure, [Index]) | Returns an angle-of-curvature value in clockwise degrees from the indexed Region structure.
GetHeight(Structure, [Index]) | Returns the height value from the indexed Cross or Region structure.
GetNPoints(Structure, [Index]) | Returns the number of points of a structure.
GetNSubregions(CompositeRegion, [Index]) | Returns the number of subregions of a composite region.
GetOperation(CompositeRegion, [Index]) | Returns the operation of the specified subregion of a composite region.
GetRadius(Structure, Index) | Returns the Radius value from the indexed Annulus or Circle structure.
GetSegmentArea(Mask, Index) | Returns the area of the indexed segment from a Mask structure, or segment 0 if no index is specified.
GetSegmentX(Mask, Index) | Returns the X coordinate of the indexed segment from a Mask structure, or segment 0 if no index is specified.
GetSegmentY(Mask, Index) | Returns the Y coordinate of the indexed segment from a Mask structure, or segment 0 if no index is specified.
GetSubregionType(CompositeRegion, Index) | Returns the shape type of the specified subregion.
GetWidth(Structure) | Returns the width value from the indexed Cross or Region structure.
GetX(Structure, [Index1], [Index2]) | Returns an x-coordinate from the indexed Annulus, Circle, Cross, Fixture, Fixtures, Line, Point or Region structure. Note: Index2, Edges-only, specifies an end point (0 or 1).
GetY(Structure, [Index1], [Index2]) | Returns the y-coordinate from the indexed Annulus, Circle, Cross, Fixture, Fixtures, Line, Point or Region structure. Note: Index2, Edges-only, specifies an end point (0 or 1).